Seuk Ki Lee

Variation block-based genomics method for crop plants

BackgroundIn contrast with wild species, cultivated crop genomes consist of reshuffled recombination blocks, which occurred by crossing and selection processes. Accordingly, recombination block-based genomics analysis can be an effective approach for the screening of target loci for agricultural traits.ResultsWe propose the variation block method, which is a three-step process for recombination block detection and comparison. The first step is to detect variations by comparing the short-read DNA sequences of the cultivar to the reference genome of the target crop. Next, sequence blocks with variation patterns are examined and defined. The boundaries between the variation-containing sequence blocks are regarded as recombination sites. All the assumed recombination sites in the cultivar set are used to split the genomes, and the resulting sequence regions are termed variation blocks. Finally, the genomes are compared using the variation blocks. The variation block method identified recurring recombination blocks accurately and successfully represented block-level diversities in the publicly available genomes of 31 soybean and 23 rice accessions. The practicality of this approach was demonstrated by the identification of a putative locus determining soybean hilum color.ConclusionsWe suggest that the variation block method is an efficient genomics method for the recombination block-level comparison of crop genomes. We expect that this method will facilitate the development of crop genomics by bringing genomics technologies to the field of crop breeding.

A correlation between tocopherol content and antioxidant activity in seeds and germinating seeds of soybean cultivars

BACKGROUND Tocopherols are crucial lipid-soluble antioxidants and essential nutrients. There is increasing interest in the biofortification of crops with vitamin E for reducing micronutrient malnutrition. However, relatively little is known about the development of soybean cultivars with high levels of tocopherol through combined breeding. RESULT Tocopherol contents of seeds and germinating seeds of 28 Korean soybean cultivars were analyzed and evaluated for health-promoting activities. Total tocopherol concentrations ranged from 203.9 to 503.1 µg g⁻¹ in seeds and from 20.1 to 230.1 µg g⁻¹ in germinating seeds. The traditional landraces of HaNagari (HN, 503.1 µg g⁻¹), Orialtae (OL, 486.6 µg g⁻¹), SuMoktae (SM, 476.5 µg g⁻¹) and SoRitae (SR, 475.5 µg g⁻¹) showed high levels of tocopherol content. The contents of the four isomers of tocopherol in seeds and germinating seeds were correlated with lipid peroxidation. The γ- and δ-tocopherol contents in seeds were related to 1,1-diphenyl-2-picrylhydrazyl free radical scavenging activity (0.434; P < 0.01 and 0.373; P < 0.05). CONCLUSION Total tocopherol content was higher in soybean landraces as compared with modern cultivars developed by cross-breeding. These results suggest that soybean breeding is necessary to increase tocopherol levels.

Quality and Antioxidant Characteristics of Cooked Rice Influenced by the Mixing Rate of Glutinous Rice and Cooking Methods

찹쌀을 첨가한 밥의 식미와 기능성 함량을 높이고자 하여 첨가비율에 따른 취반방법을 달리하여 밥을 제조하고 그 취반특성과 항산화활성을 분석하였다. 찹쌀 첨가비율에 따른 호화특성은 첨가비율이 증가함에 따라 유의적으로 감소하는 경향을 나타내었다. 수분결합력과 팽윤력은 찹쌀 첨가비율이 증가함에 따라 유의적으...

Quality Characteristics of Rice Cultivars Suitable for Rice Beer

본 연구에서는 쌀맥주 가공에 적합한 쌀 품종을 선정하기 위해 연질미 품종인 한가루, 설갱과 초다수성 품종인 다산1호 및 안다의 품질특성을 살펴보고 이를 이용하여 쌀맥주를 제조한 후 가공특성을 살펴보았다. 원료 쌀의 수분함량은 연질미인 한가루 및 설갱이 각각 14.48 및 14.62%로 다산1호 및 안다보다 높게 나타났...